QtPainter Error Paint device returned engine ==0, type 3 ,Painter not active
21,893
Solution 1
QPainter::begin: Paint device returned engine == 0, type: 3
The error means that the image you're trying to paint is a null image. Use isNull
on cou
to check this.
The cause of image being null may be the wrong height
and largeur
params when the image is constructed, or you're out of memory
Solution 2
QPaintEngine* eng = cou->painterEngine();
if(eng) {
// create QPainter ...
}
Author by
Admin
Updated on July 05, 2022Comments
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Admin almost 2 years
I'm trying to paint some points of my image and I don't know why it doesn't work. I have defined a QImage and I want to modify some points.
QImage *cou= new QImage(height,largeur,QImage::Format_Mono); cou->fill(1); QPainter *fig=new QPainter (cou); for (i=0;i<size_;i++) { fig-> drawPoint(floor(propa[i]),nbmax[i]); }
When I execute the code I obtain
QPainter::begin: Paint device returned engine == 0, type: 3
and in the following lines:
QPainter::drawPoints: Painter not active
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Nikolay Mihaylov almost 8 yearsPerhaps some explanation to your answer would be helpful for OP and future visitors of this page?